What Is a Concrete Screw

Concrete screws (also known as Tapcon screws) are a quick, easy and incredibly strong way to fasten to concrete. They eliminate the need for hammering and require no anchor or shield to install.

Just drill a special-size pilot hole (see package for bit size) and drive the screw's super-hard, high-profile threads into masonry like concrete, mortar joints, and hollow brick or block.

Size

Concrete screws are light-duty masonry fasteners used to anchor materials to poured concrete, brick, cement block and other masonry. They are available in 3/16" and 1/4" diameters with lengths up to 3 3/4". Both hex head and Phillips flat head options are available for each size of concrete screw.

To install the screw properly, a hole must be drilled in the base material. This requires the use of a carbide bit that meets specific tolerances for the screw size being installed. If a drill bit that is too large is used, the screw will not have sufficient holding values.

It is also important to ensure that the screw has a minimum embedment of 1". Installing the screw too shallow will wear the threads and compromise its performance. Use this calculator to determine the appropriate bit size for your tapcon screw.
Threads

A concrete screw’s threads tap into a pre-drilled hole in concrete, cement, brick, and cinder block/masonry to eliminate the need for an anchor. They have a double lead with alternating raised and lowered threads that have notches cut into them, as well as a diamond-shaped nail-type point. They are case hardened to maximize thread strength while preventing damage to the base material.

They are often referred to as self tapping screws, because they do not require a shield or anchor during installation and are driven into concrete with a power screwdriver without the need for hammering. They are ideal for light- to medium-duty applications such as furring strips, electrical boxes, conduit clamps, and more.

Unlike some masonry fasteners, concrete screws are not susceptible to hydrogen embrittlement. However, it is important to ensure that you are purchasing an ETA tested product and not a generic version of this type of fastener. These non-ETA products are more likely to develop hydrogen embrittlement when used in wet or external applications and can cause failure.

Head

The head of a concrete screw is full and rounded unlike the pointed tip of wood screws. Masonry and concrete screws are not designed to go into the base material without a pilot hole so their heads are full and rounded.

Tapcon masonry and concrete screws are coated with a blue polymer or made from 410 stainless steel to protect against corrosion in indoor and outdoor environments. They are rust resistant and can withstand high moisture levels.

When used properly, a concrete screw can be the fastest and strongest method for fastening furring strips, windows and doors, conduit clamps and more to poured concrete, brick and block. Drill a special-size pilot hole (see the package for the exact bit size) and then drive in the concrete screw with a power drill until the hex or Phillips head is tight against the fixture being fastened. Avoid stripping the threads in the concrete by not applying excessive torque and turning the screw by hand for the last couple of revolutions.
Drilling

Unlike many other screws, concrete screws require a special bit that creates a pilot hole. This allows the screw to cut its own threads as it is driven in, resulting in a strong hold that doesn't need an anchor pre-installed in the substrate.

Concrete screws, also known as masonry screws or anchor screws, provide a simple, fast and easy method for attaching furring strips, windows, doors, conduit clamps and electrical boxes to a concrete, brick or cinder block wall or floor. They are case hardened to maximize thread strength and designed with a double lead, alternating raised and lowered threads that have notches cut into them, and a diamond-shaped nail-type point.

When installing concrete screws, always use the correct carbide drill bit size and make sure the hole is at least 1/4-inch deeper than the screw needs to fit. Avoid overtightening and clean the hole after installation.